Add support for in-container master for macvlans

Signed-off-by: mmirecki <mmirecki@redhat.com>

plugins/main/macvlan/macvlan.go

@@ -41,6 +41,7 @@ type NetConf struct {
 	Mode       string `json:"mode"`
 	MTU        int    `json:"mtu"`
 	Mac        string `json:"mac,omitempty"`
+	LinkContNs bool   `json:"linkInContainer,omitempty"`
 
 	RuntimeConfig struct {
 		Mac string `json:"mac,omitempty"`
@@ -79,13 +80,36 @@ func getDefaultRouteInterfaceName() (string, error) {
 	return "", fmt.Errorf("no default route interface found")
 }
 
-func loadConf(bytes []byte, envArgs string) (*NetConf, string, error) {
+func getNamespacedDefaultRouteInterfaceName(namespace string, inContainer bool) (string, error) {
+	if !inContainer {
+		return getDefaultRouteInterfaceName()
+	}
+	netns, err := ns.GetNS(namespace)
+	if err != nil {
+		return "", fmt.Errorf("failed to open netns %q: %v", netns, err)
+	}
+	defer netns.Close()
+	var defaultRouteInterface string
+	err = netns.Do(func(_ ns.NetNS) error {
+		defaultRouteInterface, err = getDefaultRouteInterfaceName()
+		if err != nil {
+			return err
+		}
+		return nil
+	})
+	if err != nil {
+		return "", err
+	}
+	return defaultRouteInterface, nil
+}
+
+func loadConf(args *skel.CmdArgs, envArgs string) (*NetConf, string, error) {
 	n := &NetConf{}
-	if err := json.Unmarshal(bytes, n); err != nil {
+	if err := json.Unmarshal(args.StdinData, n); err != nil {
 		return nil, "", fmt.Errorf("failed to load netconf: %v", err)
 	}
 	if n.Master == "" {
-		defaultRouteInterface, err := getDefaultRouteInterfaceName()
+		defaultRouteInterface, err := getNamespacedDefaultRouteInterfaceName(args.Netns, n.LinkContNs)
 		if err != nil {
 			return nil, "", err
 		}
@@ -93,7 +117,7 @@ func loadConf(bytes []byte, envArgs string) (*NetConf, string, error) {
 	}
 
 	// check existing and MTU of master interface
-	masterMTU, err := getMTUByName(n.Master)
+	masterMTU, err := getMTUByName(n.Master, args.Netns, n.LinkContNs)
 	if err != nil {
 		return nil, "", err
 	}
@@ -120,8 +144,23 @@ func loadConf(bytes []byte, envArgs string) (*NetConf, string, error) {
 	return n, n.CNIVersion, nil
 }
 
-func getMTUByName(ifName string) (int, error) {
+func getMTUByName(ifName string, namespace string, inContainer bool) (int, error) {
-	link, err := netlink.LinkByName(ifName)
+	var link netlink.Link
+	var err error
+	if inContainer {
+		netns, err := ns.GetNS(namespace)
+		if err != nil {
+			return 0, fmt.Errorf("failed to open netns %q: %v", netns, err)
+		}
+		defer netns.Close()
+
+		err = netns.Do(func(_ ns.NetNS) error {
+			link, err = netlink.LinkByName(ifName)
+			return err
+		})
+	} else {
+		link, err = netlink.LinkByName(ifName)
+	}
 	if err != nil {
 		return 0, err
 	}
@@ -166,7 +205,15 @@ func createMacvlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Inter
 		return nil, err
 	}
 
-	m, err := netlink.LinkByName(conf.Master)
+	var m netlink.Link
+	if conf.LinkContNs {
+		err = netns.Do(func(_ ns.NetNS) error {
+			m, err = netlink.LinkByName(conf.Master)
+			return err
+		})
+	} else {
+		m, err = netlink.LinkByName(conf.Master)
+	}
 	if err != nil {
 		return nil, fmt.Errorf("failed to lookup master %q: %v", conf.Master, err)
 	}
@@ -198,7 +245,16 @@ func createMacvlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Inter
 		Mode:      mode,
 	}
 
-	if err := netlink.LinkAdd(mv); err != nil {
+	if conf.LinkContNs {
+		err = netns.Do(func(_ ns.NetNS) error {
+			return netlink.LinkAdd(mv)
+		})
+	} else {
+		if err = netlink.LinkAdd(mv); err != nil {
+			return nil, fmt.Errorf("failed to create macvlan: %v", err)
+		}
+	}
+	if err != nil {
 		return nil, fmt.Errorf("failed to create macvlan: %v", err)
 	}
 
@@ -228,7 +284,7 @@ func createMacvlan(conf *NetConf, ifName string, netns ns.NetNS) (*current.Inter
 }
 
 func cmdAdd(args *skel.CmdArgs) error {
-	n, cniVersion, err := loadConf(args.StdinData, args.Args)
+	n, cniVersion, err := loadConf(args, args.Args)
 	if err != nil {
 		return err
 	}
@@ -329,7 +385,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 }
 
 func cmdDel(args *skel.CmdArgs) error {
-	n, _, err := loadConf(args.StdinData, args.Args)
+	n, _, err := loadConf(args, args.Args)
 	if err != nil {
 		return err
 	}
@@ -378,7 +434,7 @@ func main() {
 
 func cmdCheck(args *skel.CmdArgs) error {
 
-	n, _, err := loadConf(args.StdinData, args.Args)
+	n, _, err := loadConf(args, args.Args)
 	if err != nil {
 		return err
 	}
@@ -429,7 +485,15 @@ func cmdCheck(args *skel.CmdArgs) error {
 			contMap.Sandbox, args.Netns)
 	}
 
-	m, err := netlink.LinkByName(n.Master)
+	var m netlink.Link
+	if n.LinkContNs {
+		err = netns.Do(func(_ ns.NetNS) error {
+			m, err = netlink.LinkByName(n.Master)
+			return err
+		})
+	} else {
+		m, err = netlink.LinkByName(n.Master)
+	}
 	if err != nil {
 		return fmt.Errorf("failed to lookup master %q: %v", n.Master, err)
 	}

plugins/main/macvlan/macvlan_test.go

@@ -38,6 +38,7 @@ import (
 )
 
 const MASTER_NAME = "eth0"
+const MASTER_NAME_INCONTAINER = "eth1"
 
 type Net struct {
 	Name       string                `json:"name"`
@@ -54,6 +55,7 @@ type Net struct {
 	DNS           types.DNS              `json:"dns"`
 	RawPrevResult map[string]interface{} `json:"prevResult,omitempty"`
 	PrevResult    types100.Result        `json:"-"`
+	LinkContNs    bool                   `json:"linkInContainer"`
 }
 
 func buildOneConfig(netName string, cniVersion string, orig *Net, prevResult types.Result) (*Net, error) {
@@ -216,6 +218,22 @@ var _ = Describe("macvlan Operations", func() {
 			return nil
 		})
 		Expect(err).NotTo(HaveOccurred())
+
+		err = targetNS.Do(func(ns.NetNS) error {
+			defer GinkgoRecover()
+
+			// Add master
+			err = netlink.LinkAdd(&netlink.Dummy{
+				LinkAttrs: netlink.LinkAttrs{
+					Name: MASTER_NAME_INCONTAINER,
+				},
+			})
+			Expect(err).NotTo(HaveOccurred())
+			_, err = netlink.LinkByName(MASTER_NAME_INCONTAINER)
+			Expect(err).NotTo(HaveOccurred())
+			return nil
+		})
+		Expect(err).NotTo(HaveOccurred())
 	})
 
 	AfterEach(func() {
@@ -225,7 +243,17 @@ var _ = Describe("macvlan Operations", func() {
 		Expect(targetNS.Close()).To(Succeed())
 		Expect(testutils.UnmountNS(targetNS)).To(Succeed())
 	})
-
+	f, t := false, true
+	for _, inContainer := range []*bool{&f, &t, nil} {
+		isInContainer := inContainer
+		masterInterface := MASTER_NAME
+		if inContainer != nil && *inContainer {
+			masterInterface = MASTER_NAME_INCONTAINER
+		}
+		linkInContainer := ""
+		if isInContainer != nil {
+			linkInContainer = fmt.Sprintf("\"linkInContainer\": %t,", *isInContainer)
+		}
 		for _, ver := range testutils.AllSpecVersions {
 			// Redefine ver inside for scope so real value is picked up by each dynamically defined It()
 			// See Gingkgo's "Patterns for dynamically generating tests" documentation.
@@ -238,9 +266,10 @@ var _ = Describe("macvlan Operations", func() {
 						Name:       "testConfig",
 						Type:       "macvlan",
 					},
-				Master: MASTER_NAME,
+					Master:     masterInterface,
 					Mode:       "bridge",
 					MTU:        1500,
+					LinkContNs: isInContainer != nil && *isInContainer,
 				}
 
 				err := originalNS.Do(func(ns.NetNS) error {
@@ -272,12 +301,13 @@ var _ = Describe("macvlan Operations", func() {
 			    "name": "mynet",
 			    "type": "macvlan",
 			    "master": "%s",
+			    %s
 			    "ipam": {
 				"type": "host-local",
 				"subnet": "10.1.2.0/24",
 				"dataDir": "%s"
 			    }
-			}`, ver, MASTER_NAME, dataDir)
+			}`, ver, masterInterface, linkInContainer, dataDir)
 
 				args := &skel.CmdArgs{
 					ContainerID: "dummy",
@@ -352,12 +382,13 @@ var _ = Describe("macvlan Operations", func() {
 			    "name": "mynet",
 			    "type": "macvlan",
 			    "master": "%s",
+			    %s
 			    "ipam": {
 				"type": "host-local",
 				"subnet": "10.1.2.0/24",
 				"dataDir": "%s"
 			    }
-			}`, ver, MASTER_NAME, dataDir)
+			}`, ver, masterInterface, linkInContainer, dataDir)
 
 				args := &skel.CmdArgs{
 					ContainerID: "dummy",
@@ -387,8 +418,9 @@ var _ = Describe("macvlan Operations", func() {
 			    "name": "mynet",
 			    "type": "macvlan",
 			    "master": "%s",
+			    %s
 			    "ipam": {}
-			}`, ver, MASTER_NAME)
+			}`, ver, masterInterface, linkInContainer)
 
 				args := &skel.CmdArgs{
 					ContainerID: "dummy",
@@ -463,12 +495,13 @@ var _ = Describe("macvlan Operations", func() {
 			    "name": "macvlanTestv4",
 			    "type": "macvlan",
 			    "master": "%s",
+			    %s
 			    "ipam": {
 				"type": "host-local",
 				"ranges": [[ {"subnet": "10.1.2.0/24", "gateway": "10.1.2.1"} ]],
 				"dataDir": "%s"
 			    }
-			}`, ver, MASTER_NAME, dataDir)
+			}`, ver, masterInterface, linkInContainer, dataDir)
 
 				args := &skel.CmdArgs{
 					ContainerID: "dummy",
@@ -576,12 +609,13 @@ var _ = Describe("macvlan Operations", func() {
 			    "cniVersion": "%s",
 			    "name": "mynet",
 			    "type": "macvlan",
+			    %s
 			    "ipam": {
 				"type": "host-local",
 				"subnet": "10.1.2.0/24",
 				"dataDir": "%s"
 			    }
-			}`, ver, dataDir)
+			}`, ver, linkInContainer, dataDir)
 
 				args := &skel.CmdArgs{
 					ContainerID: "dummy",
@@ -589,12 +623,16 @@ var _ = Describe("macvlan Operations", func() {
 					IfName:      IFNAME,
 					StdinData:   []byte(conf),
 				}
+				currentNs := originalNS
+				if isInContainer != nil && *isInContainer {
+					currentNs = targetNS
+				}
 
-			// Make MASTER_NAME as default route interface
+				// Make master as default route interface
-			err := originalNS.Do(func(ns.NetNS) error {
+				err := currentNs.Do(func(ns.NetNS) error {
 					defer GinkgoRecover()
 
-				link, err := netlink.LinkByName(MASTER_NAME)
+					link, err := netlink.LinkByName(masterInterface)
 					Expect(err).NotTo(HaveOccurred())
 					err = netlink.LinkSetUp(link)
 					Expect(err).NotTo(HaveOccurred())
@@ -686,8 +724,9 @@ var _ = Describe("macvlan Operations", func() {
 			    "name": "mynet",
 			    "type": "macvlan",
 			    "master": "%s",
+			    %s
 			    "ipam": {}
-			}`, ver, MASTER_NAME)
+			}`, ver, masterInterface, linkInContainer)
 
 				args := &skel.CmdArgs{
 					ContainerID: "dummy",
@@ -771,8 +810,9 @@ var _ = Describe("macvlan Operations", func() {
 				"name": "mynet",
 				"type": "macvlan",
 				"master": "%s",
+				%s
 				"ipam": {}
-			}`, ver, MASTER_NAME)
+			}`, ver, masterInterface, linkInContainer)
 
 				args := &skel.CmdArgs{
 					ContainerID: "dummy",
@@ -840,4 +880,5 @@ var _ = Describe("macvlan Operations", func() {
 				Expect(err).NotTo(HaveOccurred())
 			})
 		}
+	}
 })